1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method.
2. Description of the Related Art
For example, Japanese Patent Application Laid-open No. 2008-236169 discloses a technique in which a format of an input image is converted based on the features obtained from an image area thereof, and the converted image is decomposed into a multilayer structure that includes a character image, a natural image, and a mask image (selection data) that indicates which of the character image and the natural image is selected. Thus, the data amount is reduced while maintaining the edge of the character and smooth image quality in the natural image area.
Mail sending and receiving systems generally set an upper limit of the data capacity for sending and receiving data in order to prevent speed reduction of the system caused by sending and receiving a large amount of data, problems in which other accounts cannot be used because the disk capacity of the system is used up, and similar problems.
In such situations, when data exceeding the upper limit of the data capacity is to be sent, the process is usually failed at the sending side. On the other hand, when data exceeding the upper limit of the data capacity at the receiving side is sent, the process succeeds at the sending side but fails at the receiving side. As a result, the data cannot be sent.
In the related-arts described above, it is desirable to control the data amount of the multilayer structure data generated by compression utilizing the multilayer structure at equal to or less than a predetermined or a designated limited amount, not only for sending and receiving mails, but also for utilizing the data. Moreover, the output of data with less image degradation is desirable under the control of the capacity of image data sent and received.
Japanese Patent No. 3765177 discloses a technique in which data is divided into stripe shaped areas depending on the buffer size at the receiving side and is sent so as not to exceed the limitation of the buffer capacity during multilayer image conversion. During the sending, a start line or an end line of lines in which all pixels in one line are in a predetermined color is detected, and the data is divided by the lines so as not to cause displacements at the boundary between the divided stripe shaped areas.
Japanese Patent No. 4064279 discloses a rate control technique that controls the creation of codes at a designated compressibility in a Joint Photographic Experts Group 2000 (JPEG2000) coding process. As represented in this example, JPEG2000 has scalability in resolution or image quality and readily flexibly changes a code amount created by reducing the resolution or the image quality of data from that of its original data.